There is often a requirement to provide an in-ground or, at least in part, sub-surface chamber for example to house or allow access to utilities such as electricity, water, sewage, telecommunications, gas and the like. Such chambers may also be needed for other applications where a chamber is required below a surface, whether in ground or otherwise.
The chambers provide a convenient way to contain what is required in the chamber in a way that is effectively taking up space that is otherwise not used. In most situations a sub-surface location is also convenient because of access and proximity to the utility or similar the chamber is to service or contain.
Typically such chambers are in or below the surface of a roadway, footpath or similar location. However, such chambers may also be, at least in part, below a floor or other surface of a construction. For example, they may provide access to a subfloor chamber or void on a floor or otherwise above the ground.
The chambers are typically entirely enclosed except for an aperture which is normally dosed by a removable and or lockable access hatch. Such access hatches are referred to variously as manholes, utility hatches, maintenance hatches, inspection hatches and access hatches. The chambers are referred to variously as manholes, utility holes or vaults, maintenance holes, cable chambers, inspection chambers, access chambers or confined spaces. Normally the upper surfaces of the access hatch and its surrounding support frame lie substantially flush with the upper surface of the area within which they are located, for example a footpath, floor roadway or similar.
Typically such chambers when they are placed cannot, or are not, placed with a great deal of accuracy, particularly for the access hatch into the chamber. This is either because of the construction methods used, the weight of the chamber or degree of skill in placing it, or because the exact location of the access hatch is not known, or the final form of the ground surrounding the access hatch and its cover is not known. For example, the final surface height below which the sub-surface chamber is located may be of different height or slope.
There may be a need to change the height and or angle the upper surfaces of the access hatch present after they are installed. This may occur for example when there is a need to re-surface the surrounding surfaces, for example when road works occur.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.
It is therefore an object of the present invention to provide an improved adjustable access hatch frame, or to overcome the above shortcomings or address the above desiderata, or to at least provide the public with a useful choice.